Researchers from the University of Chicago have proposed that Venus may have hosted oceans long before Earth life began, a conclusion highlighted in a study published by the Proceedings of the National Academy of Sciences. This work adds a new dimension to our understanding of Venus and its early climate, suggesting that a habitable environment might have existed there in the distant past.
Today, Venus is characterized by a dry, oxygen-poor atmosphere and extreme surface conditions. Past investigations have attempted to reconstruct Venus’s climatic history using various modeling approaches. Depending on the assumptions and data fed into those models, the resulting climate scenarios varied widely, sometimes painting very different pictures of how Venus evolved over time.
In the latest research, the authors built a climate model grounded on the premise that Venus once possessed a standing ocean and conditions favorable to the emergence of life. To test this idea, they ran the simulation 94,080 times, employing three distinct starting configurations to explore a wide range of possible histories for the planet’s climate and hydrosphere.
The findings indicate that Venus has remained uninhabited for more than seven tenths of its history, a figure that surpasses several earlier estimates by a substantial margin. This suggests that, even if water droplets once covered the planet, long eras passed without life taking hold, reshaping our view of Venus’s habitability window.
According to the model, any ocean on Venus likely disappeared around three billion years ago. The simulations point to a maximum ocean depth of roughly 300 meters when averaged across the planet, a relatively shallow ocean by planetary standards but potentially significant for early climate dynamics and chemistry.
While Earth is widely believed to have hosted life for roughly 3.5 to 4 billion years, the possibility remains that a liquid-water stage on Venus three billion years ago could have created niches where life might have briefly arisen. The new study emphasizes how sensitive a planet’s habitability is to its early oceans and atmospheric evolution, and it invites continued inquiry into Venus’s hidden past and the processes that shaped its current sulfurous, dry state.